LG MZ-42PZ44

[markc]

HI,
I have a problem with this set, the picture was dark and a replacement ZSUS panel cured the fault.
But after a few days the ZSUS panel failed again. I have replaced this, but the 2nd panel has now failed.
Could anyone suggest was is dammaging the ZSUS panel? Is is the plasma screen itself?

Thanks
Mark

[mulja]

HI,
I have a problem with this set, the picture was dark and a replacement ZSUS panel cured the fault.
But after a few days the ZSUS panel failed again. I have replaced this, but the 2nd panel has now failed.
Could anyone suggest was is dammaging the ZSUS panel? Is is the plasma screen itself?

Thanks
Mark

Hi
Check the voltage on P3 at botton of Zsus board pin8 must 15v
if this voltage is to low then this is problem why your ZSUS board go faulty
Let me know what reading you get?

[markc]

Thanks for the information. I will check that & let you know.

Mark

[markc]

Voltage at Pin 8 is 10.42V!

[mulja]

Voltage at Pin 8 is 10.42V!

Always check this voltage before you change ZSUS if voltage to low then your new ZSUS will blow again after 1-4 weeks voltage on PIN8 must be 15v this voltage come from YSUS board IC16 (15v regulator)
you need replaced C72 (25v 33mkf) beside IC16...

Good luck

[markc]

I have replaced C72, but this made no difference.
I have now found that the 15V supply comes from IC19 not IC16.
The supply to this IC is low at 12.4V.
Does anyone have a circuit for this set or at least the YSUS board?

[daz]

change C37 + C78 as well but all 33mf caps in this area need to be checked with an esr meter
hope this helps
daz

[markc]

I have replaced 8 33uf capacitors around IC 17/19. The 15v rail now reads 13.9v or 14.6 v with the ZSUZ panel disconnected. Does this sound correct?
I have yet to replace the faulty ZSUS panel, but will not do that untill I am sure about this 15V supply.

Mark